Sci Rep. 2026 May 27. doi: 10.1038/s41598-026-53896-4. Online ahead of print.
ABSTRACT
Both frailty and symptomatic knee osteoarthritis (SKOA) are prevalent among older adults, with a greater incidence noted in women. The present study aimed to classify the trajectory types pertaining to the Frailty Index (FI) in postmenopausal women, explore the longitudinal correlational link among different FI trajectory profiles as well as the likelihood of developing SKOA, and evaluate the predictive value of FI trajectories for SKOA along with the robustness of this association. A long-term prospective follow-up investigation was conducted on the basis of the CHARLS cohort of postmenopausal women. Latent Class Growth Modeling (LCGM) was applied to classify the FI trajectory patterns across five waves from 2011 to 2020. Differences in the cumulative incidence risk of SKOA among trajectory subgroups were evaluated using Kaplan-Meier survival curves paired with the log-rank statistical test. The strength of this association was assessed using Cox proportional hazards regression models. Model performance across FI trajectories, as well as baseline frailty, was assessed and contrasted using ROC curves, Net Reclassification Improvement (NRI), and Integrated Discrimination Improvement (IDI). E-value estimation, subgroup analyses, and sensitivity analyses were performed to gauge the robustness of this association. For this investigation, data pertaining to 4636 postmenopausal women within the CHARLS study cohort were analyzed, with a systematic comparison of the predictive capacity of FI trajectories and baseline frailty status in assessing SKOA. The results showed that both FI trajectories and baseline frailty status showed statistically significant correlations with SKOA. Specifically, in contrast to the low-baseline slight-increase trajectory subgroup (Class 1), the high-baseline consistently rising trajectory subgroup (Class 3) exhibited the greatest likelihood of developing SKOA (HR: 3.86, 95% CI: 3.19-4.68), followed by the moderate-baseline gentle-increase trajectory group (Class 2) (HR: 3.35, 95% CI: 2.98-3.77). In comparison with baseline frailty, FI trajectories exhibited stronger predictive capability, as evaluated by the ROC curve, NRI, and IDI. Additional analyses, such as E-value calculations, subgroup analyses, and multiple sensitivity analyses, validated the stability of these relationships. The findings from this investigation highlight the significance of frailty and FI trajectories in evaluating SKOA among postmenopausal women.
PMID:42204258 | DOI:10.1038/s41598-026-53896-4
